US 7431995 B2
The present invention provides a receptacle (30) for a therapeutic fluid susceptible to deterioration on exposure to a gas such as oxygen or carbon dioxide. The receptacle (30) has walls of sheet material each including at least one layer forming a barrier essentially impermeable to such gas, and a seal sealing the walls together in a region thereof. A transfer tube (40) is sealed in the seal having a proximal end in the receptacle (30), a distal end accessible from outside the receptacle (30), a flow passage (56) extending between said proximal and distal ends, and a closure (54) blocking flow through the flow passage (56) adapted to be pierced by a tubular needle for transfer of therapeutic through the needle. The transfer tube (40) and closure (54) are essentially impermeable to said gas.
1. A multiple layer polymeric structure consisting of:
a first layer of an ethylene vinyl alcohol copolymer having first and second sides; and
a second solution contact layer of a modified ethylene vinyl acetate copolymer attached to the first side of the first layer, the second layer having a thickness of greater than 1.6 mils.
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18. A multiple layer polymeric structure consisting of:
an outside layer selected from the group consisting of polyamides, polyesters and combinations thereof;
a core layer having a first side and a second side of an ethylene vinyl alcohol copolymer; and
a sealing solution contact layer of a modified ethylene vinyl acetate copolymer wherein the outside layer is attached to the first side of the core layer and the sealing layer is attached to the second side of the core layer.
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This application claims the benefit of provisional application Ser. No. 60/284,277, filed Apr. 17, 2001, which is incorporated by reference and made a part hereof.
The present invention relates to a high gas barrier primary receptacle system, and more particularly to a receptacle system for medical solutions.
There is an ever increasing number of therapeutic fluids being developed for delivery by a flexible receptacle. Many of these therapeutic fluids are sensitive as they degrade or react with gases such as oxygen and carbon dioxide. These therapeutic fluids must be protected from contact by such gases to maintain the efficacy of the therapeutic fluid.
For example, hemoglobin solutions are known to lose their ability to function as blood substitutes during storage. A hemoglobin solution loses its ability to function as a blood substitute because of spontaneous transformation of oxyhemoglobin in the solution to methemoglobin, a physiologically inactive form of hemoglobin which does not function as a blood substitute by releasing oxygen into a patient's bloodstream. To improve shelf life, the blood substitutes industry delays loss of function by refrigerating or freezing the solutions, or controlling the oxygenation state of the hemoglobin within the solution.
Therapeutic hemoglobin solutions are typically oxygenated, stored frozen in conventional oxygen-permeable, 200 ml plastic solution bags, and thawed to room temperature hours before use.
WO 99/15289 describes a multiple layer structure for fabricating medical products. The layer structure has a core layer of an ethylene vinyl alcohol copolymer, a solution contact layer of a polyolefin positioned on a first side of the core layer, an outer layer positioned on a second side of the core layer opposite the solution contact layer, the outer layer being selected from the group consisting of polyamides, polyesters and polyolefins, and a tie layer on each side of the core layer. The tie layer is 0.2-1.2 mils in thickness, and is the only layer of the structure which may be composed of ethylene vinyl acetate.
U.S. Pat. No. 6,271,351 describes a method of storing deoxyhemoglobin in a container which is said to exhibit low oxygen permeability. The container is composed of a layered structure including ethylene vinyl alcohol, but does not include ethylene vinyl acetate.
There is a need for containers having minimal oxygen permeability which would enable deoxygenated hemoglobin solutions to be stored for weeks or months at room temperature and then used as a blood substitute.
Receptacles used for the shipping, storing, and delivery of liquids, such as medical or therapeutic fluids, are often fabricated from single-ply or multiple-ply polymeric materials. Two sheets of these materials are placed in overlapping relationship and the overlapping sheets are bonded at their outer peripheries to define a chamber or pouch for containing liquids. It is also possible to extrude these materials as a tube and to seal longitudinally spaced portions of the tube to define chambers between two adjacent seals. Typically, the materials are joined along their inner surfaces using bonding techniques such as heat sealing, radio-frequency sealing, thermal transfer welding, adhesive sealing, solvent bonding, sonic sealing, and laser welding.
It is also common to provide such receptacles with access ports to provide access to the interior of the receptacle. Access ports typically take the form of one or more end ports (transfer tubes) inserted between the sidewalls of the receptacle or panel ports attached to a sidewall of the receptacle. The end ports typically have a fluid passageway with a closure wall positioned inside the passageway to form a fluid tight seal of the receptacle. The closure, typically in the form of a membrane, must be punctured by an access needle or “spike” to allow for delivery of the contents of the receptacle.
Conventional flexible solution receptacles employing end port designs typically use flexible PVC or soft polyolefins such as LDPE to construct the port tubes. Such materials have sufficient elasticity to grip the outside of an access spike to retain the spike during fluid delivery. The inner diameter of the end ports are dimensioned to be smaller than the outer diameter of the access device. Due to the ductility of PVC or LDPE, the port tube can expand about the outside of the access spike to form an interference fit therewith. However, such receptacle and port closure systems are readily permeated by oxygen and other gases such as carbon dioxide. If such receptacles are to be utilized to house a gas sensitive liquid, such packages must utilize a gas barrier overwrap material.
To provide a stand-alone gas barrier primary receptacle, all components of the receptacle system should be fabricated using barrier material. For medical applications where such receptacles are typically disposed of by incineration, it is desirable to construct the receptacle system components from non-halogen containing polymers. Halogen containing compounds have the potential for creating inorganic acids upon incineration. Further, for medical applications, it is also desirable to construct the receptacle system components from polymers having a low quantity of low molecular weight additives, such as plasticizers, as such low molecular weight components can potentially leach out into the fluids contained or transported therein.
It is well known that certain materials provide a high resistance to the ingress of oxygen or other gases. For example, ethylene vinyl alcohol (EVOH) provides a high barrier to the ingress of oxygen. However, EVOH provides a significant design challenge for use in flexible receptacle systems as EVOH is also know to be a very rigid material. A port tube containing a significant quantity of EVOH will have insufficient elasticity to expand around an access device. Thus, such an EVOH containing port tube cannot be dimensioned to be smaller in diameter than an access device.
Due to the variation in the outer diameter dimensions of access devices commercially, it is also difficult to design a single port tube to have an appropriate diameter to form an interference fit with all access devices commercially available. The spike holder or needle holder has sufficient elasomeric properties to form around an access device and form a grasping hold of the access device. The present invention is provided to solve these and other problems.
The present invention provides a receptacle for a therapeutic fluid susceptible to deterioration on exposure to a gas such as oxygen or carbon dioxide. The receptacle has walls of sheet material each including at least one layer forming a barrier essentially impermeable to said gas, and a seal sealing the walls together in a region thereof. A transfer tube is sealed in the seal having a proximal end in the receptacle, a distal end accessible from outside the receptacle, a flow passage extending between said proximal and distal ends, and a closure blocking flow through said flow passage adapted to be pierced by a tubular needle for transfer of therapeutic through the needle. The transfer tube and closure are essentially impermeable to said gas.
The present invention further provides a transfer tube for attachment to a receptacle adapted to hold a fluent therapeutic susceptible to deterioration on exposure to gas such as oxygen or carbon dioxide. The transfer tube has a tubular body having a proximal end, a distal end opposite the proximal end, a flow passage extending between said proximal and distal ends adapted to communicate with said receptacle, and a closure blocking flow through the flow passage and adapted to be pierced by a tubular needle for transfer of therapeutic through the needle. The tubular body and closure are essentially impermeable to said gas.
The present invention is also directed to a needle holder for application to the distal end of a transfer tube of a receptacle particularly adapted to hold a fluent therapeutic susceptible to deterioration on exposure to gas such as oxygen or carbon dioxide. The needle holder is adapted to hold in place the carrier of a transfer needle with the needle piercing the transfer tube. The holder has a body having a first annular wall defining a first cavity at a first end of the body, a second annular wall defining a second cavity at a second end of the body, and a flow passage extending between the two cavities, the first annular wall being sized for an interference fit with said transfer tube to releasably attach the needle holder to the transfer tube, and the second annular wall being sized for an interference fit with said needle carrier to releasably attach the needle carrier to the needle holder in a position in which needle is disposed in said flow passage.
Additional features, advantages, and other aspects and attributes of the present invention will be discussed with reference to the following drawings and accompanying specification.
While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.
What is meant by “flowable material” is a material that will flow by the force of gravity. Flowable materials therefore include both liquid items and powdered or granular items and the like. Flowable materials receptacles find particular use for storage and delivery of medical or therapeutic fluids and include, but are not limited to, I.V. receptacles, peritoneal dialysis drain and fill receptacles, blood receptacles, blood product receptacles, blood substitute receptacles, nutritional receptacles, food receptacles and the like.
While it is contemplated the port tube 52 can have any number of layers, in a preferred form of the invention the port tube 52 will include either a discrete layer of a barrier material or a blend layer including a barrier material. The barrier material will present a barrier to the passage of gasses or water vapor transmission, and, in a preferred form of the invention, will reduce the passage rate of oxygen therethrough. It is also desirable that all materials in the solution contact layer, and more preferably all materials used in the tubing, be free of halogens, plasticizers or other low-molecular weight or water soluble components that can leach out into the solutions transferred through the tubing. Suitable barrier materials include ethylene vinyl alcohol copolymers having an ethylene content of from about 25% to about 45% by mole percent, more preferably from about 28% to about 36% by mole percent and most preferably from about 30% to about 34% by mole percent.
In an even more preferred form of the invention, the port tube 52 will have multiple layers.
In a preferred form of the invention, the multiple layer transfer tube or port tube 52 will have a discrete layer of a barrier material with the remaining layers being selected from polyolefins. The layers of the tube can be positioned in any order, however, in a preferred form of the invention, the barrier layer is not positioned as the outside layer 60. Thus, the layers of a three layer tube can be positioned in one of six orders selected from the group: first/second/third, first/third/second, second/first/third, second/third/first, third/first/second, and third/second/first. Further, in tube embodiments having more than two layers, the tube 52 can be symmetrical or asymmetrical from a material aspect and from a thickness of layers aspect.
Suitable polyolefins include homopolymers, copolymers and terpolymers obtained using, at least in part, monomers selected from α-olefins having from 2 to 12 carbons. One particularly suitable polyolefin is an ethylene and α-olefin interpolymer (which sometimes shall be referred to as a copolymer). Suitable ethylene and α-olefin interpolymers preferably have a density, as measured by ASTM D-792 of less than about 0.915 g/cc and are commonly referred to as very low density polyethylene (VLDPE), ultra low density ethylene (ULDPE) and the like. The α-olefin should have from 3-17 carbons, more preferably from 4-12 and most preferably 4-8 carbons. In a preferred form of the invention, the ethylene and α-olefin copolymers are obtained using single site catalysts. Suitable single site catalyst systems, among others, are those disclosed in U.S. Pat. Nos. 5,783,638 and 5,272,236. Suitable ethylene and α-olefin copolymers include those sold by Dow Chemical Company under the AFFINITY trademark, Dupont-Dow under the ENGAGE trademark and Exxon under the EXACT and PLASTOMER trademarks.
The polyolefins also include modified polyolefins and modified olefins blended with unmodified olefins. Suitable modified polyolefins are typically polyethylene or polyethylene copolymers. The polyethylenes can be ULDPE, low density (LDPE), linear low density (LLDPE), medium density polyethylene (MDPE), and high density polyethylenes (HDPE). The modified polyethylenes may have a density from 0.850-0.95 g/cc. The polyethylene may be modified by grafting or otherwise chemically, electronically or physically associating a group of carboxylic acids, and carboxylic acid anhydrides. Suitable modifying groups include, for example, maleic acid, fumaric acid, itaconic acid, citraconic acid, allylsuccinic acid, cyclohex-4-ene-1,2-dicarboxylic acid, 4-methylcyclohex-4-ene-1,2-dicarboxylic acid, bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, x-methylbicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhyride, allylsuccinic anhydride, citraconic anhydride, allylsuccinic anhydride, cyclohex-4-ene-1,2-dicarboxylic anhydride, 4-methylcyclohex-4-ene-1,2-dicarboxylic anhydride, bicyclo[2.2.1]hept-5-ene2,3-dicarboxylic anhydride, and x-methylbicyclo[2.2.1]hept-5-ene-2,2-dicarboxylic anhydride.
Examples of other modifying groups include C1-C8 alkyl esters or glycidyl ester derivatives of unsaturated carboxylic acids such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, glycidal methacrylate, monoethyl maleate, diethyl maleate, monomethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, monomethyl itaconate, and diethylitaconate; amide derivatives of unsaturated carboxylic acids such as acrylamide, methacrylamide, maleicmonoamide, maleic diamide, maleic N-monoethylamide, maleic N,N-dietylamide, maleic N-monobutylamide, maleic N,N dibutylamide, fumaric monoamide, fumaric diamide, fumaric N-monoethylamide, fumaric N,N-diethylamide, fumaric N-monobutylamide and fumaric N,N-dibutylamide; imide derivatives of unsaturated carboxylic acids such as maleimide, N-butymaleimide and N-phenylmaleimide; and metal salts of unsaturated carboxylic acids such as sodium acrylate, sodium methacrylate, potassium acrylate and potassium methacrylate. More preferably, the polyolefin is modified by a fused ring carboxylic anhydride and most preferably a maleic anhydride.
The polyolefins also include ethylene vinyl acetate copolymers, modified ethylene vinyl acetate copolymers and blends thereof. The modified EVA has an associated modifying group selected from the above listed modifying groups.
In one preferred form of the invention, the tube 52 has a solution contact layer 64 of a modified EVA copolymer sold by DuPont Packaging under the trademark BYNELŽ CXA, a core layer 62 of an EVOH and an outside layer 60 of a modified EVA, again preferably CXA. Such a structure is symmetrical from a materials standpoint. According to a preferred form of the invention, such tubing will have layers of the following thickness ranges: outside layer 60 from about 0.002 inches to about 0.042 inches, preferably about 0.010 inches, the core layer 62 from about 0.016 inches to about 0.056 inches, preferably about 0.039 inches, and the solution contact layer 64 of from about 0.002 inches to about 0.042 inches, preferably about 0.010 inches.
In another preferred form of the invention, the tube 52 has a solution contact layer 64 of an EVOH, a core layer 62 of a modified EVA and preferably BYNELŽ CXA and an outside or outermost layer 60 of an ethylene and α-olefin copolymer. Such a structure is symmetrical from a materials standpoint. The tube layers can have various relative thicknesses. According to a preferred form of the invention, tube 52 will have layers of the following thickness ranges: outside layer 60 from about 0.002 inches to about 0.042 inches; the core layer 62 from about 0.002 inches to about 0.042 inches; and the solution contact layer 64 from about 0.016 inches to about 0.056 inches. The outermost layer 60 of EVA is well suited for bonding to the transfer tube, especially upon heat sealing.
In a further preferred form, the tube 52 has a solution contact layer 64 of BYNELŽ CXA, a core layer 62 of EVOH, and an outside layer 60 of a blend of 50% ULDPE and 50% CXA. Such tubing will have layers of the following thickness ranges: outside layer 60 from about 0.002 inches to about 0.042 inches, preferably about 0.010 inches; the core layer 62 from about 0.016 inches to about 0.056 inches, preferably about 0.039 inches; and the solution contact layer 64 of from about 0.002 inches to about 0.042 inches, preferably about 0.010 inches.
In a preferred form of the invention, the port tube 52 shall have the following dimensions: inside diameter from about 0.100 inches to about 0.500 inches and the wall thickness shall be from about 0.020 inches to about 0.064 inches. The port tube 52 can be prepared by injection molding, extrusion, coextrusion or other polymer processing techniques well known in the art.
Turning our attention now to the closure 54, the membrane film forming the closure 54 can have any number of layers, but in a preferred form of the invention has multiple layers. The membrane film 54, in a preferred form of the invention, shall have a barrier layer as defined above.
Suitable polyamides include those obtained from a ring-opening reaction of lactams having from 4-12 carbons. This group of polyamides therefore includes, but is not limited to, nylon 6, nylon 10 and nylon 12.
Acceptable polyamides also include aliphatic polyamides resulting from the condensation reaction of di-amines having a carbon number within a range of 2-13, aliphatic polyamides resulting from a condensation reaction of di-acids having a carbon number within a range of 2-13, polyamides resulting from the condensation reaction of dimer fatty acids, and amide containing copolymers. Thus, suitable aliphatic polyamides include, for example, nylon 66, nylon 6,10 and dimer fatty acid polyamides.
Suitable polyesters include polycondensation products of di- or polycarboxylic acids and di or poly hydroxy alcohols or alkylene oxides. Preferably, the polyesters are a condensation product of ethylene glycol and a saturated carboxylic acid such as ortho or isophthalic acids and adipic acid. More preferably the polyesters include polyethyleneterephthalates produced by condensation of ethylene glycol and terephthalic acid; polybutyleneterephthalates produced by a condensations of 1,4-butanediol and terephthalic acid; and polyethyleneterephthalate copolymers and polybutyleneterephthalate copolymers which have a third component of an acid component such as phthalic acid, isophthalic acid, sebacic acid, adipic acid, azelaic acid, glutaric acid, succinic acid, oxalic acid, etc.; and a diol component such as 1,4-cyclohexanedimethanol, diethyleneglycol, propyleneglycol, etc. and blended mixtures thereof.
In a preferred form of the invention, the membrane structure shall have five layers as shown in
Further, the structure shown in
In another preferred form, the membrane structure has four layers as shown in
The outer layer 128 has a thickness of a range of about 0.0003 to 0.0007 inches, and preferably about 0.0005 inches. The third layer 130 has a thickness range of between 0.0003 to 0.0007 inches, and preferably about 0.0005 inches. The second layer 132 has a thickness range of between 0.0007 to 0.0013 inches, and preferably about 0.001 inches. The inner layer 134 has a thickness of between 0.006 and 0.01 inches, and preferably about 0.008 inches. The membrane film can be formed by extrusion, coextrusion, lamination, extrusion coating, orother polymer processing technique well known in the art.
Turning our attention now to the receptacle 30 (
In a preferred form of the invention, the sidewalls 80 are of a multiple layer structure and can include the material structures as shown in
The receptacle 30 shall have the following physical properties: modulus of elasticity of the sidewall of the receptacle is less than 60,000 psi and more preferably less than 40,000 psi; is suitable of storing an oxygen sensitive composition for at least about 6 months, more preferably at least about 1 year, more preferably at least about 2 years and even more preferably at least about 3 years; is capable of achieving these storage periods at temperatures of about room temperature and more preferably from 5° C. to about 45° C.
Turning our attention now to
It should be understood that a port tube 52 having any of the constructions described above can be combined with a closure 54 having any of the constructions described above. Thus, an assembly of a port tube 52 having any number of layers and a closure 54 having two layers, three layers or more is contemplated by the present invention. It is also contemplated that a port tube 52 having two layers, three layers or more could be combined with a membrane film 54 having any number of layers.
The spike holder 50 (which also may be referred to as a needle holder) is shown in
In a preferred form of the invention, the spike holder 50 has an outwardly extending flange 118 at an intermediate portion thereof. The flange 118 is positioned generally at the intersection of the first chamber 110 and the second chamber 112. The flange 118 has a first surface 120 which is textured to facilitate handling and manipulation of the holder. In one embodiment, this texture is provided by a plurality of buttresses 122 around the first annular wall of the body 100. In a preferred form of the invention, the flange 118 is generally circular in cross-sectional shape and the buttresses 122 are circumferentially spaced about the first surface 120. The buttresses are shown having a generally tear-drop shape, however, they could be of numerous different shapes without departing from the present invention. The buttresses are provided to form a gripping surface for those handling the spike holder 50. It may also be desirable to add an internal shoulder or other feature to the spike holder 50 to limit the extent the transfer tube can be inserted into the flow passage.
The spike holder 50 is formed from a polyolefin as defined above and more particularly is an ethylene and α-olefin copolymer. The spike holder 50 can also have a textured or matte finish on a portion or the entire outer surface 124 of the holder 50 for ease of handling. The spike holder 50 can be formed by any suitable polymer forming technique known to those skilled in the art and preferably the spike holder 50 is formed by injection molding. The spike holder 50 can also include a membrane film 54′ positioned in the passageway 114 in lieu of or in addition to the membrane 54.
In a preferred form of the invention, the spike holder 50 is formed directly over the end portion 116 of the port tube/membrane film assemblies 40 described above. Such a process is conventional and referred to as an overmolding process. The overmolding process includes the steps of: (1) providing a tubing as set forth above; providing a mold for forming a spike holder; inserting a portion 116 of the tubing 52 into the mold; and supplying polymeric material to the mold to form a spike holder on the tubing.
In an embodiment of the invention, the tubing, closure, and/or container sidewalls are comprised of a multilayer polymeric structure which includes a first layer of an ethylene vinyl alcohol copolymer having first and second sides, and a second layer of a modified ethylene vinyl acetate copolymer attached to the first side of the first layer. The second layer has a thickness of greater than 1.2 mils, preferably at least 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0 mils. The polymeric structure optionally includes a third layer attached to the second side of the first layer. Preferably, the third layer comprises a polyamide or polyester as described herein. In one embodiment, the sidewalls of a container include a core layer, outside layer, or solution contact layer comprising a modified ethylene vinyl acetate copolymer as described herein. In another embodiment, the polymeric structure comprises an outside layer of a polyamide or polyester, a core layer of an ethylene vinyl alcohol copolymer, and a sealing layer of a modified ethylene vinyl acetate copolymer, wherein the core layer is between the outside and sealing layers. This polymeric structure optionally includes one or more tie layers attached to the core layer.
The receptacles of the present invention are used to store deoxyhemoglobin solutions or other therapeutic fluids which react with oxygen. The receptacles are filled with the solution in a low oxygen or oxygen free environment, sealed, and then stored at about 5 to 45° C. for weeks or months prior to use. Conventional methods of filling and sealing containers in a low oxygen or oxygen free environment are suitable for the invention. After storage, the deoxyhemoglobin solution contains less than 15% methemoglobin and is physiologically acceptable for administration to a patient. In a preferred embodiment, the deoxyhemoglobin solutions are stored at room temperature and ambient conditions.
The following is an example of the present invention and is not intended to limit the claims of the present invention.
Several 250 ml volume receptacles were fabricated as shown in
It is understood that, given the above description of the embodiments of the invention, various modifications may be made by one skilled in the art. Such modifications are intended to be encompassed by the claims below.